IBN Rushd on Galen and the new drugs spread by the Arabs

The rise of the Abbasid dynasty created uniquely favorable economic conditions for exchange of all kinds. Muslim rulers took advantage of the presence within their empire of various kinds of specialised knowledge and techniques, and in so doing generated a revolution, spreading agricultural innovations and the use of new drugs, the vast majority of which were imported from South-East Asia, India, China and Zanzibar. The present article focuses on the examination of medicinal substances known in the Muslim world that were not mentioned by Classical writers. Some Muslim physicians, most of them Andalusian, who dealt with the identification and re-evaluation of medicinal substances - writers such as Ibn Juljul (10^th century) and al-Idrīsī (12^th century) - were aware of the absence of many drugs in the Greek medical literature and devoted works to the discussion of such missing drugs. Another important source for our knowledge is Ibn Rushd, also known as Averroes (12^th ca.). In his major work on medicine, the al-kulliyyāt (Generalities), written between 1153 and 1169, he devoted a chapter to the drugs not mentioned by Galen. Ibn Rushd's list consists of fortyone drugs, twenty of which are identical to drugs that feature in Ibn Juljul's and al-Idrīsī's lists. This article presents the potential hidden in Ibn Rushd's list and assesses and reconstructs the list of drugs that were distributed by the Arabs. In future studies, we intend to gauge the extent of this phenomenon. The list is diverse, and consists of medicinal plants, perfumes, and spices, domesticated plants, drugs of animal and mineral origin, and compounds. These affected the pharmacology and diet of the pre-modern world for hundreds of years, and many of the simples are still in use in modern societies today.